Refractory and reinforcement therefor



-'10, 1955 R. A. EDWARDS ETAL 3,199,473

REFRACTORY AND REINFORCEMENT THEREFOR Filed Jan. 2, 1964 2 Sheets-Sheet 1 l0 2 INVENTORKS/ BY DONALD c. BURKLO 2| ROBERT A. EDWARDS 1965 R. A. EDWARDS ETAL 3,199,478

REFRACTORY AND REINFORCEMENT THEREFOR Filed Jan. 2, 1964 2 Sheets-Sheet 2 INVENTOR(5) ROBERT A. EDWARDS DONALD c. BURKLO United States Patet 3,19,47S REFRACTSRY AND REENFGRCEMENT THEREFGR Robert A. Edwards and Donald C. Burirlo, (Ioiumhiana,

Ohio, assignors to Kaiser Aluminum dz Chemical Corporation, Oakland, Calif., a corporation of Delaware Filed Jan. 2, 1964, Ser. No. 335,331 9 Qlaizns. (Cl. 1109) There has been a trend in recent years towards the construction of furnaces, for example open hearth furnaces, of refractories which are suspended from or attached to structural supports outside the furnace. For example, the roof of a furnace may be constructed of refractory shapes suspended by means of metallic hangers inserted in recesses in the cold ends of the shapes, the hangers being attached to overhead beams. This type of construction is particularly prevalent in the use of the so-called basic or nonacid refractories, made from materials such as magnesite, periclase, chromite, and mixtures of two or more of these. Refractory shapes made of such basic or nonacid materials have a tendency during their period of use in a furnace, particularly a steel-making furnace, to crack and allow relatively large pieces of refractory to drop off the furnace wall or roof. It has been found that this relatively rapid dropping away of large chunks of basic refractories can be largely prevented by incorporating an internal or co-rnolded steel reinforcement. Often this reinforcement takes the form of a plate bent into a U shape, the base or Web of the U lying in one face of the refractory shape and the arms or sides of the U being embedded in the refractory. Such reinforcements are generally known as U-core reinforcements. When such U-core reinforcements are embedded in brick having a hanger-receiving recess within the refractory mass, there is a tendency for the refractory material by which the shape is suspended to be weaker and break off from the main body of material, allowing the entire shape to fall from the suspension.

It has now been found that a reinforcement constructed and used according to this invention permits the making of a refractory shape adapted to be suspended by a hanger inserted in a recess therein which is metallically reinforced above such hanger recess while at the same time the metal reinforcement is protected by refractory material in the region of the hanger recess. The device also reinforces the channel against deformation or bending during pressing of the brick or shape.

This invention will be understood in the light of the following description and the drawings, in which:

FIGURE 1 is a perspective view of one embodiment of a metallic reinforcement according to this invention;

FIGURE 2 is a top plan view of a metallic reinforcement according to this invention;

FIGURE 2a is a partial plan view similar to FIGURE 2 but showing an alternative embodiment;

FIGURE 3 is a plan view of a refractory shape in the form of a straight brick, containing a metallic reinforcement according to this invention, the reinforcement being inverted from the postion shown in FIGURE 2;

FTGURE 4- is a cross-sectional view taken along the line t-4 of FIGURE 3; and

FIGURE 5 is a cross-sectional view taken along the line 55 of FIGURE 3.

One embodiment of a metallic insert of this invention comprises a U channel 11 having a back or web 12 of generally rectangular shape and having opposed longitudinal edges 13 and 13'. Integral with and attached to the web 12 along the edges 13 and 13' are two arms 14- and 15 of generally rectangular or oblong form and having edges 13 and 13', respectively, attached to the 3,199,478 Patented Aug. 10, 1865 insert '18 lies substantially perpendicular to both the web 12 and the arms 14- and 15. The insert 18 is of a length such that it extends at each end beyond the slots 19 and 2% in the arms 14 and 15. The width of the insert 18 is preferably slightly less than the length of the slot 19 in arm 14 such that at each side it lies closely adjacent the respective end of slot 19. This is so that insert 18 will be held without excessive play. Insert 18 is held against longitudinal displacement through the slots, for example by means of projections such as dimples, bosses, or struckout portions 21 and 21' placed so as to lie adjacent opposite sides of the arm 14 when the insert 18 has been pushed through the slot 19. Each projection is of greater height than the distance between the surface of the insert and the long edge of the slot, in order to lock the insert in position.

The metal reinforcement of this invention will generally be inserted in a refractory shape at the time the shape is formed, as by comolding under pressure. The reinforcement is particularly useful in a refractory shape 22 which has a recess 23 adapted to receive a hanger (not shown). One way in which this co-molding may be accomplished is by placing the U-core reinforcement in the bottom die or cavity of a conventional brick press with its web 12 against the base of the die and its arms 14 and 15 extending upwardly, and then filling the die cavity with refractory mix to be compressed or compacted. When the upper die or punch of the press is lowered to compress thev refractory mix in the die box, the refractory material is forced into compacted relationship with the metal reinforcement and co-molded therewith. It is advantageous also to provide struck-out tongues or apertures or like means in the channel to provide interlocking engagement with the refractory mass, in the known manner. When the refractory shape is to have a hanger-receiving recess, this can be formed by a projection on the upper die or punch, the recess being placed so that the insert 18 lies between the recess and the nearer end of the refractory shape. It will be understood that, with this forming procedure, the web 12 of the U-channel 11 will be exposed at the face 27 of the refractory shape 22, the recess 23 opening onto the opposite face 23 of the refractory shape 22.

Alternatively, the reinforcement can be inserted by being pushed down into the refractory material from above, being, for example, carried by the upper die during its downward stroke. In this method of molding, it is essential that the insert 1% be held in the slots 1? and 21'} when the arms 14 and 15 are disposed in a downward direction. To this end, the slot 19 is terminated short of the free edge 16 of the arm 14. While in this case the slot 2-0 may also terminate short of the free edge 17 of the arm 15, it need not do so but may extend tothe free edge 1'7 as shown in FIGURE 1. The embodiment with the slot 2i) extending to the free edge 17 makes it easier to assemble the insert 18 and the U- channel 11. Also, the slots 19 and 26 need not extend all the way to the attached edges 13 and 13 of the arms 14 and 15. However, if the slot 19 terminates short of the attached edge 13 of the arm 14, then it is desirable that the slot 20 should terminate a substantially equal distance short of the attacl ed edge 13' of the arm 15. However, when the slot id terminates at the attached edge 13- of the arm 1 it is not essential that the slot 2% terminate at the attached edge 13 of arm 15. In this instance, the slot 2d can continue as slot 2t) in the web 12. The extra length of slot 2d makes the U-channel 11 more resilient in the neighborhood of the slot 2t) and makes it easier to pass insert 13 with its buttons or dimples 21 and 2?, through the slot 2?). Of course, when slot 269 extends to free edge 17 it is not necessary to push dimples El and 21' through slot 2i to assembly U-channel it and insert 1.8.

it will be understood that the retaining dimples 21 and 231i need not both lie adjacent opposite sides of the arm id but that one dimple, 231", for example, can be placed so as to lie adjacent the exterior face 26 of arm 15 when the insert it; is in place. The dimples or struckout portions 21 and 21' can be replaced by other retaining means such as rivets, spot welds, and the like.

In the case where the U-channel Till is made of relatively heavy metal, for example steel, it may not be resilient enough in the region of the slots 1% and 2% to permit passage therethrough of dimples or projections 21 and 21'. In this case, it will be preferred that the projection of dimples 21 be resilient, for example a resilient lip or struckout portion of the metal insert is, said projection depressing toward the plane of the insert it; under pressure when it is passed through slot 1%, for example. After clearing slot 19, the struckout portion 21 resiliently returns to its outstanding position and locks against the exterior face 24 of arm 14, thus resisting the return the insert through the slot 19. The second or companion projection 21 can be of the same resilient struckout construction, but looking or positively catching against the inner face 25 of flange 14 or, alternatively, a similar resilient struckout portion 21" may look or butt against the exterior face 26 of arm 15. However, it will be understood that the projections 21' or 21" need not be resilient when it is not required that they pass through either slot 19 or slot 2% during assembly of the insert 18 to the U-channel ill, as when slot 2% extends to free edge 17 of arm 15.

It is an advantage of the metal reinforcement of this invention that, by its use, one can make a refractory shape adapted to be suspended from a hanger, the shape having much less tendency to break while in use and being one in which essentially all the weight of the shape is carried on interlocked pieces of metal. Thus, if the refractory material itself cracks in the region of the recess, there is assurance that the entire shape will not drop off the hanger. Although the device has been described herein as incorporated in a straight brick having four side faces of which the first and second pair of opposite faces are generally parallel to each other, and two end faces, it will be understood that it can also be incoroprated in other shapes such as wedge, arch or the like shapes. When empolyed as reinforcement in a wedge or straight hanger brick, the web of the channel member is disposed flush with one longitudinal or side face of a first pair of side faces and the flanges or arms extend at least a major portion of the width of the brick to the opposite side face and generally parallel to the second pair of side faces; and the reinforcing insert is disposed between a hanger-receiving recess adjacent one end face and the near or adjacent end face. Also, channel inserts of other than rectangular configuration of the web or side flanges or both can be employed. The inserts of this invention are particularly useful for incorporation in basic and nonacid bricks, especially such as are made of periclase, magnesia, or mixtures of chromite and magnesia or periclase grains. It is to be noted that when portions or projections are struckout of the metal, as described above, the metal plate insert is cut or pierced in such striking out, and the projection is of such configuration that the metal edge of the cut-out portion abuts the flange of the channel in a curved path, locking the insert in place.

Having now described the invention, what is claimed 1. A reinforcement for a refractory shape comprising: a channel having a web with two opposed longitudinal edges and first and second arms, each said arm having an edge attached to one of said opposed edges of the web and a free edge opposed to said attached edge, said first arm having a slot adjacent one end and said second arm having a slot adjacent said one end; and an insert extending through said slots, the length of the insert being greater than the distance between the arms at the slots, said insert having retaining means to hold it within the slots.

2-. A reinforcement for a refractory shape comprising: a channel having a web of substantially rectangular form having two opposed longitudinal edges and first and second arms of substantially rectangular form, each said arm having an edge attached to one of said opposed edges of the web and a free edge opposed to said attached edge, said first arm having a slot adjacent one end and extending substantially perpendicular to the web and terminating short of the free edge of the arm, said second arm having a slot adjacent one end, and substantially perpendicular to the web, each of said slots being substantially the same distance from one end of the channel; and an insert extending through said slots, the width of the insert being slightly less than the length of the slot in said first arm and the length of the insert being greater than the distance between the arms at the slots, said insert having retaining means to hold it within the slots.

3. A reinforcement for a refractory shape comprising: a channel having a web of substantially rectangular form having two opposed longitudinal edges and first and second arms of substantially rectangular form, each said arm having an edge attached to one of said opposed edges of the web and a free edge opposed to said attached edge, said first arm having a slot extending substantially perpendicular to the web and terminating short of the free edge of the arm, said second arm having a slot extending substantially perpendicular to the web and extending to the free edge of the second arm, the termination of both slots nearer the web being substantially the same distance from the web; and an insert extending through said slots, the width of the insert being slightly less than the length of the slot in said first arm and the length of the ins rt being greater than the distance between the arms at the slots, said insert having retaining means to hold it within the slots.

4. A reinforcement for a refractory shape comprising: a channel having a web of substantially rectangular form having two opposed longitudinal edges and first and second arms of substantially rectangular form each having edge attached to one of said opposed edges of the web and a free edge opposed to said attached edge, said first arm having a slot extending substantially perpendicular to the web and terminating short of the free edge of the arm, said second arm having a slot extending substantially perepndicular to the web and extending to the free edge of the second arm, the termination of both slots nearer the Web being substantially the same distance from the web, each of said slots being substantially the same distance from one end of the channel; and an insert extending through said slots, the width of the insert being slightly less than the length of the slot in said first arm and the length of the insert being greater than the distance between the arms at the slots, said insert having retaining means to hold it within the slots.

5. A reinforcement for a refractory shape comprising: a channel having a web of substantially rectangular form having two opposed longitudinal edges and first and second arms of substantially rectangular form each having an edge attached to one of said opposed edges of the web and a free edge opposed to said attached edge, said first arm having a slot extending substantially perpendicular to the web and terminating short of the free edge of the arm, said second arm having a slot extending substantially perpendicular to the web, the termination of each slot closest the web being substantially at the attached edge of the arm, said web having a slot extending over a portion of the web from the point of termination of said slot in said second arm at the attached edge of said second arm, the slot in the web being a continuation of the slot in the second arm; and an insert extending through said slots in said arms, the width of the insert being substantially equal to the length of the slot in said first arm and the length of the insert being greater than the distance between the arms at the slots said insert having retaining means to hold it within the slots.

6. A reinforcement for a refractory shape comprising: a channel having a web of substantially rectangular form having two opposed longitudinal edges and first and second arms of substantially rectangular form each having an edge attached to one of said opposed edges of the web and a free edge opposed to said attached edge, said first arm having a slot extending substantially perpendicular to the web and terminating short of the free edge of the arm, said second arm having a slot extending substantially perpendicular to the web and extending to the free edge of the second arm, the termination of each slot closest the web being substantially at the attached edge of the arm, each of said slots being substantially the same distance from one end of the channel, said web having a slot extending substantially perpendicular to said second arm from the point of termination of said slot at said attached edge of said second arm, the slot in the web being a continuation of the slot in the second arm, and an insert extending through said slots in said arms, the width of the insert being substantially equal to the length of the slot in said first arm and the length of the insert being greater than the distance between the arms at the slots, said insert having retaining means to hold it within the slots.

7. A refractory shape having an end face and opposed first and second side faces, a recess opening onto said first side face, and, embedded in said refractory, a metal reinforcement of U-shaped cross-section having a substantially rectangular web, two substantially rectangular arms adjoined to said web and an insert disposed substantially perpendicular to said web and to said side arms and retained in slots in said side arms, the web of the metal reinforcement lying in the plane of the second side face of the refractory shape, the arms being embedded in the refractory shape, and the insert being disposed in said refractory between the end face and the recess.

8. A refractory shape having two end faces and side faces, a hanger-receiving recess adjacent one end of said shape and opening onto one side face, a metal reinforcement of U-shaped cross-section embedded in said refractory and two arms adjoined to said web and disposed substantially perpendicular thereto and a metal insert disposed substantially perpendicular to said web and to said side arms and retained in slots in said arms, the webof the metal reinforcement lying in the plane of the second side face of the refractory shape, the arms being embedded in the refractory shape, said insert being longer than the distance between said side arms and less than the distance between two opposite side faces of said brick, whereby said insert is wholly embedded within said refractory shape and disposed between said one end face of said shape and said hanger-receiving recess.

9. A reinforcement for a refractory hanger shape adapted to be embedded in said shape during formation thereof comprising in combination: a channel comprising a web having an upper and a lower surface, and two side arms, each said arm being disposed substantially perpendicularly to said web and both said arms extending from the same surface of said web, a slot in each of said arms disposed in a direction substantially pendicular to said web and contained wholly within each said respective side arm, said slots being disposed adjacent one end of said channel and opposite to each other; and a flat insert disposed perpendicularly across said web and passing through both said slots, said insert extending outwardly from each slot and being adapted to being embedded wholly within said refractory shape.

References Cited by the Examiner UNITED STATES PATENTS 8/58 Mason et al. --99 5/61 Duncan 110-99 

8. A REFRACTORY SHAPE HAVING TWO ENDS FACES AND SIDE FACES, A HANGER-RECEIVING RECESS ADJACENT ONE END OF SAID SHAPE AND OPENING INTO ONE SIDE FACE, A METAL REINFORCEMENT OF U-SHAPED CROSS-SECTION EMBEDDED IN SAID REFRACTORY AND TWO ARMS ADJOINED TO SAID WEB AND DISPOSED SUBSTANTIALLY PERPENDICULAR THERETO AND A METAL INSERT DISPOSED SUBSTANTIALLY PERPENDICULAR TO SAID WEB AND TO SAID SIDE ARMS AND RETAINED IN SLOTS IN SAID ARMS, THE WEB OF THE METAL REINFORCEMENT LYING IN THE PLANE OF THE SECOND SIDE FACE OF THE REFRACTORY SHAPE, THE ARMS BEING EMBEDDED IN THE REFRACTORY SHAPE, SAID INSERT BEING LONGER THAN THE DISTANCE BETWEEN SAID SIDE ARMS AND LESS THAN THE DISTANCE BETWEEN TWO OPPOSITE SIDE FACES OF SAID BRICK, WHEREBY SAID INSERT IS WHOLLY EMBEDDED WITHIN SAID REFRACTORY SHAPE AND DISPOSED BETWEEN SAID ONE END FACE OF SAID SHAPE AND SAID HANGER-RECEIVING RECESS. 